Method for forming themain body of a catamenial tampon

ABSTRACT

A wad of fibrous material provided with a pulling string and a stem inserted therein with its one end projected outward is first compressed from opposite sides by a pair of side dies and then compressed from the front and rear by a pair of transverse dies so as to obtain a cylindrical main body of a tampon. By carrying out these two steps of compression separately, the fibrous body obtained, when used, can be swollen into an elliptical or spindlelike shape in fitting contact with the vagina.

United States Patent .1191

Yamauchi 1451 Jan. 16,1973

[54] METHOD FOR FORMING THEMAIN BODY OF A CATAMENIAL TAMPON [76] Inventor: Akira Yamauchi, 121 Tatsumachi,

' Sasayama-cho, Taki-gun, Japan {22] Filed: July 10, 1970 211 Appl. No.: 53,733

[30] Foreign Application Priority Data July 19, 1969 Japan ..44/5730l [52] US. Cl. D/144.5 [51] Int. Cl. ..A61l 15/00 [58] Field of Search ..19/I44.5; 128/285, 270

[56] References Cited UNITED STATES PATENTS 13,068,867 12/1962 Bletzinger et a1 ..l28/285 2,464,310 3/1949 l-Iarwood ..I9/I44.5

FOREIGN PATENTS OR APPLICATIONS 110,738 6/1940 Australia ..l28/285 557,035 11/1943 GreatBritairu ..128/270 Primary ExaminerDorsey Newton Attorney-Wende roth, Lind & Ponack [57] ABSTRACT A wad of fibrous material provided with a pulling string and a stem inserted therein with its one end projected outward is first compressed from opposite sides by a pair of side dies and then compressed from the front and rear by a pair of transverse dies so as to obtain a cylindrical main body of a tampon. By carrying out these two steps of compression separately, the fibrous body obtained, when used, can be swollen into an elliptical or spindlelike shape in fitting contact with the vagina.

1 Claim, 5 Drawing Figures 3/1960 Bletzinger et al l 9/l44 5 PATENTEU JAN 1 I975 AKIRA YAMAUCHI,

INVENTOR Bwhwmmlw ATTORNEYS METHOD FOR FORMING THEMAIN BODY OF A CATAMENIAL TAMPON The present invention relates to a method for forming the main body of a catamenial tampon by compressing a fibrous material.

In accordance with a conventional method for forming the main body of a catamenial tampon from a fibrous material such as absorbent cotton, the material was usually compressed into a cylindrical shape by applying external pressure thereon uniformly in radial directions by means of several pieces of pressing dies.

However, such method is not satisfactory in that it is difficult to form a smooth surfaced fibrous body since part of the material is left unpressed in edgelike form on the surface of the compressed material along the junctions of the dies. Moreover due to the difficulty to effect full compression to the deepest portion, the product obtained is liable to be deformed, and when permeated with menstrual fluids during use, the tampon of this type swells up while retaining its circular cross-sectional shape. The inevitable imperfect contact with the vaginal wall therefore results in leakage of the fluids and affords uncomfortable feel to the body cavity.

An object of the present invention is to provide the main body of a catamenial tampon which is so adapted that when permeated with fluids, the tampon can be deformed into an elliptical or spindlelike form in cross section resembling the cross-sectional configuration of the vagina, the present tampon thus being rendered highly efficie'nt and comfortable to use.

Another important object of the present invention is to provide the main body of a catamenial tampon which is completely compressed from its surface layer up to the core thereof and which is therefore least susceptible to fluffing or deformation before absorption of fluids.

Still another object of the present invention is to provide the main body of a catamenial tampon which has a smooth surface without edgelike projections so as to insure greater amenability to surface coating.

In order to fulfil the objects described, the present invention provides a method for forming a main body of tampon comprising steps of placing a wad of fibrous material between a pair of side dies disposed in facing relationship with each other, the fibrous material being provided with a suitable pulling string and a stem inserted therein at its center an axial direction withone end projected outward therefrom; subjecting said fibrous material to a first step of compression by mov-' ing the side dies toward each other; and subjecting the fibrous material thus obtained to a second step of com pression by pressing the material from the front and rear thereof so. as to produce a cylindrical body. The cylindrical fibrous body may further be compressedin axial direction by upper and lower dies to be brought -into the cylindrical opening defined by the side dies and transverse dies. Thus, by carrying out the first and second compressing operations separately, the tampon main body obtained can be deformed into an elliptical or spindlelike shape in section when permeated with menstrual fluids during use, thisinsuring snug-fit contact with the vagina for prevention of leakage of the fluids.

For a better understanding, the present invention will be described below with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view showing a fibrous material of tampon before compressing;

FIG. 2 is a perspective view showing an apparatus for forming the material into the main body of tampon;

FIG. 3 is a plan view in horizontal section showing the fibrous material as it has been subjected to a first step of compression by movable side dies;

FIG. 4 is a plan view in horizontal section showing the material as it has been subjected to a second step of compression by transverse dies subsequent to the first step of compression; and

FIG. 5 is a view in vertical section illustrating a third step of compression conducted by a pressing die as sembly including pressing rods, the view being taken along the centerline of the die assembly.

The tampon main body of the present invention comprises a fibrous material cut to a rectangular shape and a suitable string 2 attached to the fibrous material as by engagement or stitching as shown in FIG. 1. The fibrous material provided with the string 2 is then longitudinally folded into a roll to obtain a fibrous wad la, into'which a stem 7 to be described later is inserted before it is compressed by a forming apparatus as shown in FIG. 2;

The forming apparatus comprises side dies 4, 4 adapted to be moved on guides 3, 3, a pair of transverse dies 5,5 each having a concave recess of a semicircular cross section along its inner end and adapted to be slidably moved on the inner surfaces of the side dies 4,

4 when the dies 4, 4 are brought close to each other,

and upper and lower pressing dies 6, 6' adapted to be fitted into a cylindrical opening to be formed by the side dies 4, 4 and transverse dies 5, 5. As will be described later, the upper pressing die 6 is formed with a hole 8 .for inserting the stem 7, while the lower pressing die 6' is formed with a semispherical recess at its end facing the bottom of the upper die 6. Designated at 9 and 10 are pushing bars for the respective dies.

An important feature of the present invention is the provision of the stem 7 of elliptical cross section which is coaxially inserted into the center of the fibrous wad la, thestem 7 being so disposed that the longer diameter thereof is positioned parallel to the side wall of the side die 4, with the upper end 7' projected outward.

Although the stem 7 may be placed into the fibrous wad Ia before compression as already described, intended results will be obtained insofar as it is inserted at least prior to the second step of compression to be described below.

For compression, the movable side dies 4, 4 are first moved toward each other with the fibrous wad la placed therebetween, whereby the wad 1a is compressed from the opposite sides, with the stem 7 disposed therebetween, to obtain a pillarlike body lb resembling a rectangle in'cross section as seen in FIG. 3. The transverse dies 5, 5 are then actuated. The body lb is now compressed into a cylindrical body 10 as shown in FIG. 4 by the dies 5, 5 guided on the inner .faces of the side dies 4, 4. During this operation the tact with the vaginal wall for reliable prevention of leakage of menstrual fluids, uncomfortable feel during use being also substantially mitigated,

The cylindrical body 1c obtained by the second step of compression is further compressed in axial direction into a tampon main body 1d of a short length by the upper and lower dies 6, 6' as seen in FIG. 5. To effect such compression, the upper pressing die 6 and the lower pressing die 6 are moved toward each other in sliding contact with the cylindrical opening wall which is defined by the side dies 4, 4 and transverse dies 5, 5, the upper end 7' of the stem 7 passing through the hole 8 of the upper die 6.

Alternatively, the third step of compression to be performed by the upper and lower dies 6, 6 as described above can be omitted by providing stationary dies which are adapted to define the upper and lower ends of the cylindrical body lc during the second step of compression by transverse dies 5, 5. Such arrangement of the die assembly also insures substantially effective compression.

After the stem 7 is removed, a separately prepared rod may be inserted into the hole formed by the stem 7, when the tampon is to be applied to the vagina, insertion of the tampon into the vagina thus being facilitated. In addition, the hole, which is elliptical in cross section, serves to indicate the direction in which marked swelling of tampon takes place.

What is claimed is:

l. A method for forming a cylindrical main body of a tampon comprising the steps of:

longitudinally folding a fibrous material into a rollshaped fibrous wad;

positioning within the center. of said wad a longitudinal stem having an elliptical cross section such that one end thereof projects outwardly from said wad;

positioning said wad in a forming apparatus comprising a pair of substantially flat surfaced side dies disposed in facing relationship with each other, a pair of transverse dies each having a concave recess of a semicircular cross section disposed in facing relationship with each other transverse to said side dies, and upper and lower pressing dies one of which has on an inner surface thereof a semispherical recess and the other of which has therethrough a hole dimensioned to receive said stem, said wad being positioned within said apparatus such that the longer diameter sides of said elliptically cross sectioned stem are parallel with the substantially flat surfaces of said side dies;

performing a first compressing step on said wad by moving said side dies against opposite surfaces thereof;

performing a second compressing step on the once compressed wad by moving said transverse dies against the front and rear surfaces of said wad, thereby forming a cylindrical fibrous body by the pressing contact of said transverse dies, said second compressing step compressing said wad more densely between said stem and said transverse dies than between said stem and said side dies;

performing a third compressing step on said cylindrical fibrous body b moving upper and lower pressing dies towar each ot er and against said body in the axial direction thereof; and removing said stem from said thrice compressed wad; thereby providing a hole of elliptical cross section in said compress wad; thereby forming a cylindrical tampon which will swell elliptically during use. 

1. A method for forming a cylindrical main body of a tampon comprising the steps of: longitudinally folding a fibrous material into a roll-shaped fibrous wad; positioning within the center of said wad a longitudinal stem having an elliptical cross section such that one end thereof projects outwardly from said wad; positioning said wad in a forming apparatus comprising a pair of substantially flat surfaced side dies disposed in facing relationship with each other, a pair of transverse dies each having a concave recess of a semicircular cross section disposed in facing relationship with each other transverse to said side dies, and upper and lower pressing dies one of which has on an inner surface thereof a semispherical recess and the other of which has therethrough a hole dimensioned to receive said stem, said wad being positioned within said apparatus such that the longer diameter sides of said elliptically cross sectioned stem are parallel with the substantially flat surfaces of said side dies; performing a first compressing step on said wad by moving said side dies against opposite surfaces thereof; performing a second compressing step on the once compressed wad by moving said transverse dies against the front and rear surfaces of said wad, thereby forming a cylindrical fibrous body by the pressing contact of said transverse dies, said second compressing step compressing said wad more densely between said stem and said transverse dies than between said stem and said side dies; performing a third compressing step on said cylindrical fibrous body by moving upper and lower pressing dies toward each other and against said body in the axial direction thereof; and removing said stem from said thrice compressed wad; thereby providing a hole of elliptical cross section in said compress wad; thereby forming a cylindrical tampon which will swell elliptically during use. 